1. Field
The described technology relates generally to a battery module.
2. Description of Related Art
A rechargeable battery is a battery that is dischargeable and rechargeable unlike a primary battery that is not rechargeable. Low-capacity rechargeable batteries are used for a small-sized portable electronic device such as a portable phone, a notebook computer, and a camcorder and high-capacity batteries are widely used as power sources for driving motors of hybrid cars and so on.
Recently, high-output rechargeable batteries using high-energy-density non-aqueous electrolytes have been developed and the high-output rechargeable batteries are formed as high-capacity rechargeable batteries by connecting a plurality of rechargeable batteries in series such that they can be used to drive an apparatus requiring a large amount of power, for example, motors of electrical cars.
Also, one high-capacity rechargeable battery is generally composed of a plurality of rechargeable batteries connected in series and a rechargeable battery may be formed in a cylindrical shape, a prismatic shape, etc.
A rechargeable battery has a vent which is opened when an internal pressure increases to a threshold amount to prevent the rechargeable battery from exploding due to the increase in the internal pressure of the rechargeable battery.
A gas exhausted from the rechargeable battery can be exhausted to the outside. If the internal gas of the rechargeable battery is not exhausted to the outside, the rechargeable battery may explode or ignite. In order to rapidly exhaust the internal gas of the rechargeable battery, a pressure inside a housing constituting the battery module should be sufficiently low. However, when the rechargeable batteries are positioned in a sealed housing, since the internal pressure of the housing may not be low enough to rapidly exhaust the gas, the rechargeable battery can explode.
Particularly, after a vent of one rechargeable battery is opened, since the internal pressure of the housing increases, even though a vent of another rechargeable battery is opened, the gas cannot be rapidly exhausted, so the rechargeable battery can explode.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.